Palladium-Catalyzed Alkylation of sp2 and sp3 C−H Bonds with Methylboroxine and Alkylboronic Acids: Two Distinct C−H Activation Pathways
摘要:
Palladium-catalyzed alkylations of sp2 and sp3 C-H bonds with either methylboroxine or alkylboronic acids were developed. Ag2O or AgCO3 is used as a crucial oxidant and promoter for the transmetalation step. Ether, ester, alcohol, and alkene functional groups are tolerated. A new C-H activation pathway differing from the cyclometalation process is elucidated using methylboroxine as the coupling partner.
Regioselectivity-Switchable Hydroarylation of Styrenes
作者:Ke Gao、Naohiko Yoshikai
DOI:10.1021/ja108809u
日期:2011.1.26
Cobalt-phosphine and cobalt-carbene catalysts have been developed for the hydroarylation of styrenes via chelation-assisted C-H bond activation, to afford branched and linear addition products, respectively, in a highly regioselective fashion. Deuterium-labeling experiments suggested a mechanism involving reversible C-H bond cleavage and olefin insertion steps and reductive elimination as the rate-
Regioselective alkylation of 2-phenylpyridines with terminal alkenes via C–H bond activation by a rhodium catalyst
作者:Yeong-Gweon Lim、Jung-Bu Kang、Yong Hae Kim
DOI:10.1039/p19960002201
日期:——
2-Phenylpyridine 1a reacts with various terminal alkenes in the presence of a rhodium(I) complex catalyst to give the corresponding mono ortho-alkylated products 2a-i and doubly alkylated products 3a-b (9:1), The same reaction using 3-methyl-2-phenylpyridine 1b gives the mono alkylated products 2j-n exclusively under the same reaction conditions due to steric hindrance between the methyl group of the pyridine and the alkyl group of 2j-n.
[EN] TRANSITION METAL-CATALYZED ALKYLATION OF C-H BONDS WITH ORGANOBORON REAGENTS<br/>[FR] ALKYLATION À CATALYSEUR À BASE DE MÉTAL DE TRANSITION DE LIAISONS C-H AVEC DES RÉACTIFS D'ORGANOBORE
申请人:BRANDEIS UNIVERSITY MS134
公开号:WO2008024953A2
公开(公告)日:2008-02-28
[EN] One aspect of the present invention relates to methods for functionalization of 2-arylpyridine and arylpyrazoles with organoboron reagents in the presence of a transition metal catalyst to furnish alkylated arylpyridines and arylpyrazoles via regioselective functionalization of sp2 -hybridized C-H bonds at a position ortho to the point of attachment of the pyridine or pyrazole ring to the aromatic nucleus, hi other embodiments, the present invention provides for alkylation of sp3-hybridized C-H bonds in alkylpyridines. [FR] Selon un mode de réalisation, la présente invention concerne des procédés de fonctionnalisation de 2-arylpyridine et d'arylpyrazoles avec des réactifs d'organobore en présence d'un catalyseur à base de métal de transition pour obtenir des arylpyridines et des arylpyrazoles par fonctionnalisation régiosélective de liaisons C-H à hybridation sp2 en une position ortho au point de liaison du cycle pyridine ou pyrazole au noyau aromatique. Selon d'autres modes de réalisation, la présente invention concerne l'alkylation de liaisons C-H dans des alkylpyridines.